Automatic License Plate Readers (ALPR or LPR) are a relatively new tool being eagerly deployed by law enforcement agencies across the globe. For about a decade, federal, state and local agencies have been using ALPR systems to curb vehicle related offenses and solve crimes which are executed with vehicle involvement. A standard ALPR system is composed of cameras, which are mounted to the exterior of a police car, a processor, usually stored in the trunk, and a Hot List database housed on the in-car computer. As the police car passes moving or parked vehicles, the ALPR cameras scan license plates, instantaneously comparing each plate to the Hot List, a database of current plate numbers suspected of being associated with a criminal offense. If there’s a match, alarms blare and a color photo of the license plate that caused the alarm pops to the forefront of the computer screen. In most situations, the officer can easily identify the car and interdict.

For agencies currently in the market for ALPR technology, one plate reader camera scan is not equal to all others. Getting the best ALPR scan will allow officers in the field to see more in each photo associated with cars that cause an alarm. ELSAG North America’s industry-leading Mobile Plate Hunter-900® (MPH-900®) ALPR technology utilizes advanced cameras that take an all-digital “progressive scan” of each license plate, rather than the “interlaced scan” used by competitive analog systems. “Progressive scans provide the purest ALPR read,” said Nate Maloney, ELSAG’s VP of Marketing and Communications. “If you’re an officer looking for a suspect vehicle in a sea of cars or in the dark, you want as much clarity and detail in your photo as you can get.”

A progressive plate reader camera scan actually records the image of the license plate and car one line at a time until the entire composite image is captured. Interlaced images are recorded in two scans, every-other-line per scan. Image parts are then laced together forming the entire image. Interlaced image technology cannot provide as sharp an image as progressive scanning.

Additionally, progressive technology provides the best ALPR scanbecause cameras are not required to be as close to the license plate in order to capture it. Because the cameras are farther away, the composition of the image includes a substantial part of the car and its surroundings, rather than just a close up of the license plate. This larger image area provides valuable information which has proven to be critical in many cases. Law enforcement may be able to determine the make and model of the car or see distinguishing marks that could come into play during an investigation.

When it comes to public safety, seeing the sharpest, most detailed image of a suspect vehicle is critical. To find out more about ELSAG’s MPH-900 ALPR technology and why its progressive scanning provides the purest ALPR read, contact them today. www.elsag.com // info@elsag.com // 877-77-ELSAG (773.5724).